Shock absorber



Julyll, l930 c. H. FOSTER 1,769,425

SHOCK ABSORBER Filed-Jude 1 6, 1928 z sheets-sheet I Patented July 1, 193() CLAUD I-I. FOSTER, WICKLIFFE, OHIO SHQGK ABSORBER Application led June 16,

such as are interposed between the axles and bodies of automobiles for :the purpose ofv checking relative movements therebetween due to the encountering of obstacles or depressions by the wheels.

It is the general purpose and object of the invention to provide a shock absorber whichV isnot only simple of construction and economicalof production, but which will automatically etect the gripping or braking action of the brake band upon the drumrby the separation of thev bodyr and axle and which also will automaticallyy elect the release of such gripping or braking action under conditions to be pointed out hereinafter. Y A :further object of the invention is to provide a shock absorber of this typewhich is capable of withstanding and accommodating all ordinary incidents of use.

The shock absorber as specifically illustrated and described herein consists generally of a brake drum, with a pair of concentric brake bands arranged externally of the drum, and a strap operatively connected to the outer of said bands for eecting certain braking actions of the bands upon the' drum as well as a braking action of the outer of said bands upon the inner band, there being a helical spring operatively connected with the strap and with the outer band for taking in the slack o'f the strap as the vehicle members approach each other and for simultaneously moving the outer brake band to a position where it is adapted, upon separation of the vehicle inembers, to engage'the inner band.

Referring to the drawings, Fig. 1 represents'a sectional elevation of a shock absorbe]` constructed in accordance with my invention, showing the parts in the positions which they occupy when the vehicle springs are under normal riding conditions; Fig. 2 a sectional viewvcorresponding to the line 2-2 of Fig. 1; Fig. 3 a view similar torFig. 1, showing the parts of the shock absorber in the positions which they occupy when the vehicle body and axle have approachedeach other following a somewhat severe compression of 'the vehicle springs and Fig. 4 a rear eleva- 1928.Y Serial N0. 285,911.

tion ofthe said shock absorber, with certain parts broken away.'

Describing the various parts by reference characters 1 denotes one of the side frame members and 2 the axle housing of a vehicle. 3 denotes a cylindrical brake drum having a bottom or back wall, the central portion 4 of which isoliset from the peripheral portion 5, such oset portion being seated within a metaldisk 6 having a rounded peripheral flange 6a. The brake drum is secured to the side framemember 1 by means of bolts, the shanks of'which are indicated at 7 and which shanks project through openings in the parts 1, 4 and 6. vEachbolt is provided with an enlarged cylindrical head 8 within the body f of the brake drum, the opposite ends of the end 11b may be secured to the plate 12 in any convenient manner, as by means of one or more inner clamping members 13 having each a V-shaped groove atv its center adapted to engage the said end of the spring, the clamping members being riveted through the plate 12-to a plate 14 on the front of the plate 12, which plate 14 may bea name plate.

. The wall-12a telescopes over a cylindrical 'wall 15 of the rear'or inner housing member, and the latter wall merges with a rear annular wall 15a having its inner edge spaced from the central portion4 of the base of the brake drum; `The rear 'annular wallla is provided with a pair ofrearwardly or inwardly extending annular grooves 15b therein, each of which isadapted to receive a packing ring 16, which packing rings engage the portion v5 of the rear or-inner wall of the brake drum, thereby to prevent the entrance of dust into the interior of the housing which encloses the brake drum and the brake band.

Y means ofthe flanged `dish 6, 6a.

The housing constituted byrtheparts `12,

` 12L and 15, 15@ is spaced from the brake drum and is rmovable with reference thereto, for af purpose to be explained hereinafter. 17 denotes a spring metalfband having u therewithin and attached'thereto a friction band 18, the said band being of any suitable material, such as fabric belting. The spring band 17 i isgivena curvature such that 1t V'tends to Vhold the band 18 in close engagement'with the Voutersurface of the drum 3.

The composite band -is offfsuich length that,

' ential'iiange or shoulder 3? Vat its outerendy when applied to the 4 drumdts lends preferf ably will be in closeproximltyto each other."

The drum?, is'provided'with'a circumfer- 7, and with'a similarflange or shoulder 3b lat itsinner'end, which flanges or shoulders re` tainithe composite band 17, 18 upon the drum;UA

\ Surrounding Vthe band '17, 1s withal Ynl@ housing is an outer brake band 19 preferably `of fabric beltingandhaving its yends in proximity to each other. This band 1s of considerably less thicknessthan the width of theispacebetween the interior of thehousingand theband 17,y .O ne end'Aof the band s 19 is secured to the housing as by means of rivets 2Q e'xtending.through such end, and .securedfto the inner wall of the housing. This endloftheband 19 will be held outof contact` with th'ebandf17 by virtue ofthe `fact thatthespace jbetweenthe band 17 and the inner wall of the housing is considerably greater than the thickness of the band 19.

The opposite end'B of the band 19 is'built Y up by means of a fillerstrip`21 to a thickness equal-to the width ofthe'space between theinner'wall of the housing andthe band 17 ,the filler strip being secured to the band 19 by one or Vmore rivets 2 2.;` Y

i For the purpose of :causing the brake bands 17, 18and 19to function through the sepa# ration of thebody and axle,I secure tothe housing the upper end lportion 23 of Va strap Y means VV of short screwbolts 24extend1ng throrgh the strapvC, through a metalplate C. This 'strap also may be Inadeof fabric belting and has its upper end secured to bothwalls 12?*` and .15 Vofthe houslng by Y 25 on the `inner surfaceof the strap end, and

4through the walls ofthe housing'. `The lower portion of the 'strap is "looped around the axlev housing 2,' andthe extreme end 23EL of such end portion is fastened to the body of the strap by means ofU-bolts 26, plates 27,

i i and nuts28 on the ends of :thelegs .of the bolt.

In Figsland 2-the A and B are shown in thel positions-Which they occupy during ordinary `or normal riding conditions.

Owing to the fact that the housing floats with reference to the brake dru-m,"some light Y Theentranceof isfurther prevented by pressure will beI exerted through the strap C and through the built up end B of the brake band upon the drum. The opposite end A of the strap will be free from the pose of this `arrangement willbe explained hereinafter; Y

Vith thel parts constructed and arranged as described, when the wheels encounter an' obstacle which movesthe axle `toward the body, the spring 11 will move thebrake band freely in a counter-clockwisev direction around the brakedrum,taking in the slack of the strap C. No matter Vhow rapid may be the movement of the axle toward the body, or

vice versa, the spring 11is undersufficient torsion to enable it immediately to rotate the housing and thereby take in the slack of the strap and fleet the band 19 aboutthe band 17 which, beingofmaterial having a low coefficient of friction, such as brass, will not oppose any material lresistance to such movement of the band 19. At the end of the movement ofthe body and axle toward each other, the'po'sitionsof the parts of the shock absorber will be approximately as shown in Fig. 8, depending upon the extent of movement of the body and axle toward leach other. O n recoil or separation of thebody and axle, the strap C, due to the floating of the housing torwhich it is connected as well as to the somewhat yielding nature of the housing,

ywill press the'built-up end B of the strap the more quickly and strongly will the builtup endv of the brake band be pressedz against the outer surface Vof the brake band therewithin, with a corresponding-pressure of the latter band against the brakegdrum. According to the severity or rapidityof the reaction, the following. actions will occur (a) Under light reaction, following a movement of small amplitude of the body and axle toward each other, the band 19 will slide upon the outer band 17 of the composite brake band therein, exercising a slight braking action upon the drum with no vnecessary rotation of the inner brake band.

Under a more severe reaction, follow` ing a greater movement of the body and axle toward each other, the band .19 will vslide upon the band 17, 18 and the latter will also CTI lowing a correspondingly increased movement of the body toward the axle, the band 19 will be gripped so strongly upon the band 17, 18, that there will be norelative move- Y ment between the inner and outer bands, both Cal flanges 3a and 3b.

bands moving in unison and producing a maximum braking action.

However, on the hardest or most severe reaction of the vehicle springs afterimpact, the inner brake band can slide upon the drum, thereby preventing the locking of the brake bands to the drum and preventing the shearing of the attaching bolts 7, or the breakingof the strap C, or the shearing of the bolts or rivets by which the strap is attached to the housing and axle.

It is desirable that the braking action shall not continue throughout the entire range of rebound movement or reaction, as this would interfere with ease of riding and with the desirable action of the vehicle spring. rherefore, as the built-up end. B of the outer brake band approaches the position shown in Fig. 17 the pressure of such end uponv the inner band and hence of the latter band upon the drum, is relaxedV and, when the built-up end shall have passed below the point of tangency of the strap C to the housing and the pressure of t-he same against the inner brake band by the strap AC Vshall have been relaxed, further separation will be resisted only by the vehicle springs and bythe comparatively slight resistance aorded by the spring 11.

Furthermore, because of the fact that the 'housing is movable or oats with reference resilient, the end B of the brake band will always be in effective engagement with the t inner brake band and the housing when the body and axle are moving away from each other-up to the time when the end kB shall have passed below the place at which Vit is subjected to the pressure of the strap C.

The spring 11 yis normally under light compression, as well as under torsion whereby it presses the packing 16 against the back of the brake drum, thereby compensating for wear and preventing entrance of dust, etc. into the housing.

It will be noted that clearance is provided between the inner brake band 18 and the This enables the inner band to move outwardly with the outer band and with the housing and to maintain complete engagement between the outer band and the strip 17 as the housing is moved outwardly by the spring 11, due to the compression or wearing of the packing 16. Unless this clearance'is provided, it will be advisa ble to make the composite band 17, 18 some-y what wider than the band 19 so as to secure full braking contact between the inner surface of the band 19 and the exterior surface of the strip 17 while allowing the band 19v to move outwardly upon the strip 17 f In describing the invention, it has been assumed, for convenience of description, that the brake drum and housing will be carried by one of the side frame members and thatv the strap C will be secured to the upper portion of the housing and extend around such upperportion, with its lowerl end secured to the axle housing; and the terms upperv and lower have been used in connection with such description, but withoutany inten drum adapted to be securedto one of two` relatively movable vehicle members, a housing surrounding the said drum "and spaced therefrom andl movable with respect thereto, a strap connected at one end to the exterior of said housing and adapted to be connected at its other end to the other vehicle member and adapted to extend about and engage a portion of the outer surface of the housing,

a springhaving one end anchored with ree spect tothe housing and its other end con-r nected to said housing, a brake band on said drum having an anti-friction outer surface, and a brake band mounted on the first mentioned brake band and having one end secured to said housing and spaced from the first mentioned band, the opposite end ofthe second brake band substantially filling the space between the first band and the housing. y

2. A shock absorber comprising a base adapted to be secured to one of two relatively movable vehicle members, a brake: drum carried by said base, a. housing surrounding the said drum and spaced therefrom and movable with respect thereto, a strap connected at one end to the exterior of said housing and adapted to be connectedat its other end to the other vehicle member and adapted to extend about and engage a portion of the outer surface of the housing, a spring having one end anchored to the base and its other end connected to said housing, a brake band on said drum having an anti-friction outer surface, and a brake band mounted on the first mentioned brake band andl having one end secured to said housing and spaced from the first mentioned band, the opposite end of the second brake i ,band'being adapted to be .pressed ,againstthe .first-mentioned brake band bythe 'action `of the strapr on thehousing.

` 'I 3.` A e shock absorber comprising a l drum adapted `ftobesecured to one oftvvo.

i relatively movablevehicle members, a housing surrounding the said. drum and spacedl therefrom andmovable With respect thereto, t a strap connected atfone end to theeziterior onft said .housing and adapted to be connected i .at-its other end tothe other vehicleinember andfadapted to extend about and engagea portionv of the outer surface of the housing,

aspring Vhaving one `end anchored With respectlto said housing and its other end connected to said housing, a brakeiband on the saidk drum, the said band comprising an inner `inember having ai relatively high coefficient 'of frietionand an outer member of spring metalftending to hold the innerniember in mounted on the i'irst mentioned brakeband andl having one end secured tothesaid housing andfspaced from the firstmentioned band,"

the oppositev end` ofthe second brake band being adapted to be pressed againstthe firstmentioned brake .band bythe action of the strap on the housing. Y, v

4t.` Thebombination, With two relatively movable `vehicle members, of a shock absorber ycomprisingabrake drum securedfto one of said members, a brakeband surrounding the said drum-,ahousing surrounding the bralie band andbrale drum and spaced therefrom.

andmovableitovvardand from the drum, a

brake band interposed-between Ythe said nous.

ing and' the-first .mentioned brake band, one

`end ofthe` secondbrakeband being connected i tothe said housing'and being spaced from the f i au` firstl mentioned brake bandy and the oppositeend of the second band being free from `the Vhousing but substantially filling the space between the said housing and the .i'irst-inentioned brake band, a strap connected. at one end to the housing and connected at its other end to the other vehicle member and extending about and engaging aportion of the outer 7 soi end of the second brake band being connect-l surface of the housing, and a spring connected tosaid housing and adapted to rotate thesaine ina direction toltale in theslaclz of the strap ,asN the-vehicle members approach eachother and tofrotate the outer bralejband freely about the drum. and theinner brake band.

5. The combination, With tivo relatively movable vehicle members, of a shock absorber comprising a brake drum secured to one of said inembersabraireband surrounding the said drum, a housing surrounding the brake bandaiidbraleidrum and spaced therefrom and nmvable toward -andfrom the drum, a brake-bandinterposed between the said housing andthe first mentioned braleband, one

edto the said housingand being spaced from the lirst4 mentioned brake band and the `op-l iffeeear ber andextending abouttand engaging aportion ofjthe outer surface of the housing, and

means Aconnected to `said housing for rotating the same in a direction to take in the slack of the'strap asthe vehicle members approach Y eachother 4and to rotatethe outer brake band freely about; the,l drum f and `the inner brake band.VVV A y p,

6. The combination,` with tvvo rela-tively movable vehicle members, of a shock absorber comprising a brake drum secured to one of said members, a brake band surrounding the said drum, a" housing surrounding the brake band and brakedrum and spaced therefrom and movable toward-,and from the drum, a bralrelband interposed between thevsaid housing andthe first mentioned bralfe band, one end of the secondbrale band beingcoiiiiected tothe said housing and beingspaced from the first mentioned brake band the opposite end of the secondhand being free from the i housing but substantially filling the space between the saidhousing'and the first inentioned brakeband, astrap connected at one Yend to the housing and connected at its other end` to the other vehicle member and extending, about and engaging a portion of the outer surface of the housing, and a springfconnected to said housing and adapted to',rotate thel saineina direction to taire in they slack of the strap as the Vehicle members approach each other and to rotate the outer bralreband free- Vly about the drum and the inner brake band,

the exterior surface of the inner handhaving a low coefficient of friction and the inner surface ofthe outerband and the interior surface of theinner band each having a high coefficient of friction.` I

' 7. The combination, with two relatively movable vehicle members, of a shock absorber comprising abrake druinsecured to one of saidmembers, a bralre band surrounding the 'said drum, abrake band substantially surrounding the' first mentioned band, and a flexible ronnectioni between the other vehicle member and the second brake band and serving to cause the second band to exert a brakingI pressure Aagainst the first band during movements of 'a predetermined amplitude of the vehicle members, away from each other and to release such pressure when such amplitudeshall have been exceeded, and a spring connected with the outer brake band for rotating the saine ivith respect to the drum and for taking in the slackof the flexible connection during movements of the vehicle members towardeach other.

`8. The kcombination,'With two relatively movable vehicle inembers, of a shockabsorber lll) comprising a brake drum secured to one of the said members, a brake band surrounding said drum, a second brake band substantially surrounding the first mentioned band, and a flexible connection between the other vehicle ymember and the outer brake band and serving to cause the second brake band to exert a braking pressure against the first mentioned band and thereby against the drum during movements of a predetermined amplitude of the vehicle members away from each other and to release such pressurewhen such amplitude shallhave been exceeded, and a spring connected with the outer brake band for moving the same and for taking in the slack of the said flexible connection during thek latter movements of the vehicle members.

9. The combination, with two relatively movable vehicle members, of a shock absorber comprising a brake drum secured to one of the said members, a brake band surrounding said drum, a second brake band substantially surrounding the first mentioned band, and a flexible connection between the other vehicle member and the outer brake band and serving f to cause the second brake band to exert a braking pressure against the first mentioned band and thereby against the drum during movements of a predetermined amplitude of the vehicle members away from each-other and to release such pressure when such amplitude shall have been exceeded, as well as during the movements of the vehicle members toward each other, and a spring connected with the outer brake band for moving the same and for taking in the slack of the said ments of the vehicle members.

10. The combination, with two relatively movable vehicle members, of a shock absorber comprising a brake drum secured to one of the said members, a brake band surrounding the said drum, a second brake band substan-` tially surrounding the first mentioned band, and a flexible connection between the other' vehicle member and the outer brake band and serving to cause the following actions of the brake band, dependent upon the violence of the recoil movements of the vehicle axle and body :-(a) the sliding of the outer brake band upon the inner brake band, the inner brake band being practically immovable upon the drum; (b) the sliding of the outer brake band upon the inner brake band and the sliding of the latter band upon the drum; (c) the sliding of the inner band only upon the drum, the outer band moving in unison therewith, and a spring connected with the outer brake band for rotating the same with respect to the drum and the inner brake band and for taking in the slack of the flexible cony.nection during movements of the vehicle members toward each other.

11. A shock absorber adapted to be interposed between two relatively movable veflexible connection during the latter move- -having an annular wall interposed between the outer portion of the base ofthe said drum and the vehicle member to which'the said drum is attached, there being packing'interposed between said annular ywall and the drum base, a helical spring having one 'end anchored with respect to the housing and its other end connected to the cover portion of said housing, the said brake drum having circumferential retaining flanges on the cylindrical outer surface thereof, a brake band of less width than the space between said flanges and mounted `on the cylindrical surface of the drum between said iianges, a strap secured to the housing and adapted to engage the exterior of the same, and a brake band mounted on the first mentioned brake band and having one end secured to the said housing and spaced from the first mentioned band, the opposite end of the second brake band being adapted to be pressed against the first mentioned brake band by the action of the strapon the housing.

12. A shock absorber adapted to be interposed between two relatively movable vehicle members, the said shock absorber comprising a brake drum having a base by means of which it may be secured to one of said members, a housing surrounding the brake drum and enclosing the open end thereof and having an annular wall interposed between the outer portion of the base of the said drum and the vehicle member to which the said drum is attached, there being packing inter-- housing and spaced from the first mentioned band, the opposite end of the second brake band and having one end secured to the said band being arranged to be pressed against the first mentioned brake band by the action of the strap on the housing.

In testimony whereof, I hereunto afx my signature.

CLAUD H. FOSTER. 

